Re: The eye: Darwin's "cold shudder"

Stephen Jones (sejones@ibm.net)
Sat, 07 Feb 98 10:01:43 +0800

All

Darwin wrote to American botanist Asa Gray in 1860. - "The eye to
this day gives me a cold shudder, but when I think of the fine known
gradation my reason tells me I ought to conquer the odd shudder."
(Darwin C., letter to Asa Gray, February 1860, in Darwin F., ed.,
"Life and Letters of Charles Darwin", 3 vols, John Murray: London,
vol. 2, 1888, p273).

When I walked over Charles Darwin's grave in Westminster Abbey
recently, I distinctly heard him turning over! He must be
wishing he had never listened to his cook, Sir Max Busby, who
was the real author of Darwin's theory (see Bell J.S., "The Darwin
Conspiracy", Vision House: Gresham, Oregon, 1995) ;-)

Why is Chas (Sir Max's affectionate term for his protege) in such
a lather? Well it is much, much, worse than he thought. Darwin took
comfort in the fact that although:

"To suppose that the eye with all its inimitable contrivances for
adjusting the focus to different distances, for admitting different
amounts of light, and for the correction of spherical and chromatic
aberration, could have been formed by natural selection, seems, I
freely confess, absurd in the highest degree." (Darwin C., "The Origin
of Species", 6th edition, Everyman's Library, 1967 reprint, p167)

there were numerous gradations in eyes within nature:

"Reason tells me, that if numerous gradations from a simple and
imperfect eye to one complex and perfect can be shown to exist, each
grade being useful to its possessor, as is certainly the case; if, further,
the eye ever varies and the variations be inherited, as is likewise
certainly the case; and if such variations should be useful to any
animal under changing conditions of life, then the difficulty of
believing that a perfect and complex eye could be formed by natural
selection, though insuperable by our imagination, should not be
considered as subversive of the theory." (Darwin, 1967, p167)

Darwin's followers likewise took comfort that they eye had in
fact originated by natural selection at least forty times:

"eyes have evolved independently more than forty times in the animal
kingdom" (Mayr E., "The Growth of Biological Thought", 1982, p612).

"The key to understanding the process of evolution is to remember
that natural selection works in stepwise fashion. An eye didn't just
appear full-blown. It evolved stepwise, one small, modest step after
another, over a great deal of time. In fact, eyes have evolved
several times independently-in arthropods (spiders, crabs, insects,
etc.), in mollusks (snails, scallops, octopuses, etc.), and in the
vertebrates. The eyes of these three groups are built differently
and function differently, but they are eyes nonetheless. Very
likely, eye evolution began with a spot of light-sensitive nervous
tissue." (Berra T.M., "Evolution and the Myth of Creationism", 1990,
p67)

Indeed, Dawkins maintains that they eye has evolved independently
more than sixty times:

"It has been authoritatively estimated that eyes have evolved no
fewer than forty times, and probably more than sixty times,
independently in various parts of the animal kingdom. In some cases
these eyes use radically different principles. Nine distinct
principles have been recognized among the forty to sixty
independently evolved eyes."(Dawkins R., "Climbing Mount Improbable",
1996, p127)

Note the word "independently" in all three quotes. It is important
for the `blind watchmaker' theory that it has the power to build the
same thing (but slightly differently) from scratch many times. But
now it seems that they essential machinery of the eye arose only
*once*, and every eye, from insects to mammals, is just an
elaboration of that original master gene-machine, which had
everything built-in from the start to make all eyes, for all time!

Here is the abstract of the famous article, "Induction of Ectopic
Eyes by Targeted Expression of the eyeless Gene in Drosophila" by
Georg Halder, Patrick Callaerts, Walter J. Gehring, which
demonstrated that fact:

"The Drosophila gene eyeless (ey) encodes a transcription factor
With both a paired domain and a homeodomain. It is homologous to
the mouse Small eye (Pax-6) gene and to Aniridia gene in humans.
These genes share extensive sequence identity, the position of three
intron splice sites is conserved, and these genes are expressed
similarly in the developing nervous system and in the eye during
morphogenesis. Loss-of-function mutations in both the insect and in
the mammalian genes have been shown to lead to a reduction or
absence of eye structures, which suggests that ey functions in eye
morphogenesis. By targeted expression of the ey complementary
DNA in various imaginal disc primordia of Drosophila, ectopic eye
structures were induced on the wings, the legs, and on the antennae.
The ectopic eyes appeared morphologically normal and consisted of
groups of fully differentiated ommatidia with a complete set of
photoreceptor cells. These results support the proposition that ey is
the master control gene for eye morphogenesis. Because homologous
genes are present in vertebrates, ascidians, insects, cephalopods, and
nemerteans, ey may function as a master control gene throughout the
metazoa." (Halder G., Callaerts P., & Gehring W.J., "Induction of
Ectopic Eyes by Targeted Expression of the eyeless Gene in
Drosophila", Science, Vol. 267, 1988, p1788)

The article concludes that "the genetic control mechanisms of
development are much more universal than anticipated":

"The high degree of sequence conservation between the human, the
mouse, and the Drosophila genes, the similarity of the phenotypes of
Aniridia, Sey, and ey, and the similarity of the expression patterns
suggested to us that ey might be a master control gene for eye
morphogenesis that is shared by vertebrates and invertebrates (3).
Because we also found homologous genes in ascidians, cephalopods,
and nemerteans we propose that en function is universal among
Metazoa. In order to test whether the mouse gene can substitute for
the Drosophila gene, we also used the mouse Sey gene for targeted
expression in Drosophila. Similar to the results obtained for the
Drosophila ey gene, the mouse gene Sey can also induce the
formation of ectopic eye structures...As expected, the ectopic eye
structures formed contain Drosophila-type ommatidia and not mouse eye
structures....The observation that mammals and insects, which have
evolved separately for more than 500 million years, share the same
master control gene for eye morphogenesis indicates that the genetic
control mechanisms of development are much more universal than
anticipated..." (Halder, et. all, 1988, p1792)

If Darwinists thought that the eye evolving forty times independently
showed the power of natural selection, then logically the fact that
the fundamental eye machinery arose only *once*, must show the
impotence of natural selection to bring something fundamentally new
into being.

That this is a real difficulty for the Darwinists is evdident from
Dawkins reaction to it. He admits that his "message...that eyes
evolve easily and fast...might seem challenged by an intriguing set
of experimental results, recently reported by a group of workers in
Switzerland associated with Professor Walter Gehring." (Dawkins R.,
"Climbing Mount Improbable", 1996, pp174-175). Dawkins is surprised
by it: "Amazingly, the treated adult flies grew up with fully formed
compound eyes on their wings, legs, antennae and elsewhere" and "They
even work....." (pp175-176), describing it twice as "remarkable"
(p176) and "almost too startling" (p176). Rather limply he says he
doesn't think that he was "wrong to think that eyes have developed
forty times independently" and that "At least the spirit of the
statement that eyes evolve easily and at the drop of a hat remains
unscathed." (p176). This all sounds like a rear-guard action,
trying to play down an uncomfortable fact, whereas if it was
favourable to Darwinism, Dawkins would be proclaiming it on page 1,
instead of burying it in the middle of his book.

Biologist Paul Gross, in responding to an anti-Darwinist essay by
mathematician-philosopher David Berlinski, wrote that this new
evidence of a single "genetic...mechanism underdoing the embryology
of all eyes-Insects, mice, humans", was "astonishing". Berlinski
replied:

"I am in agreement with Mr. Gross when he refers to "new and
astonishing evidence" about the origin of the eye. Herewith the facts.
Halder, Callaerts, and Gehring's research group in Switzerland
discovered that the ey gene in Drosophila is virtually identical to the
genes controlling the development of the eye in mice and men. The
doctrine of convergent evolution, long a Darwinian staple, may now
be observed receding into the darkness. The same group's more
recent paper, "Induction of Ectopic Eyes by Targeted Expression of
the Eyeless Gene in Drosophila" (Science 267, 1988) is among the
most remarkable in the history of biology, demonstrating as it does
that the ey gene is related closely to the equivalent eye gene in Sea
squirts (Ascidians), Cephalopods, and Nemerteans. This strongly
suggests (the inference is almost irresistible) that ey function is
universal (universal!) among multicellular organisms, the basic design
of the eye having been their common property for over a half-billion
years. The ey gene clearly is a master control mechanism, one capable
of giving general instructions to very different organisms. No one in
possession of these facts can imagine that they support the Darwinian
theory. How could the mechanism of random variation and natural
selection have produced an instrument capable of anticipating the
course of morphological development and controlling its expression
in widely different organisms?" (Berlinski D., "Denying Darwin:
David Berlinski and Critics", Commentary, September 1996,
pp9,28,30)

How indeed? This is just one more example among an increasing body
of evidence (which I plan to publish on the Reflector), of prior
planning and genetic preprogramming in nature, that advocates of a
Darwinist `blind watchmaker' mechanism of adaptation to local
environment by a purely materialistic mechanism of genetic mutation +
natural selection, did not predict, or even expect.

[...]

Regards,

Steve

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Perth, West Australia v "Test everything." (1Thess 5:21)
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